The conventional camera obtains depth information, three-dimensional (3D) information, based on an image obtained by using a two-dimensional (2D) image sensor. Recently, a structured light method and a time of flight (TOF) method are used. The structured light method is used to measure a depth of an object by irradiating laser light on which a specific pattern has been coded onto the object, and by calculating a pattern shift amount of the reflected light. And the TOF method is used to measure a depth of an object by directly irradiating light onto the object, and by calculating time taken for the reflected light to return.
However, the structured light method has a restriction in miniaturizing the 3D camera module due to a physical size of a light transmitting portion and a light receiving portion configured to receive reflected light and using a laser optical source. This may cause a difficulty in applying the structured light method to mobile products. Further, the structured light method adopts a fixed focal lens and a passive coding device. This may cause the structured light method not to have a flexible scheme to enhance a depth resolution.
Next, the TOF method has a limitation in usage, due to a high cost of a ToF exclusive sensor which calculates a time proportional to a distance of return light, and high power consumption of an LED having its brightness modulated. Recently, a 3D camera is being presented to enhance a performance through an image synthesis with the conventional 2D camera. For instance, an RGBIR camera for measuring a 2D image and a 3D depth by a single camera is being developed. The RGBIR camera is implemented by combining a 2D camera and a 3D IR camera for depth measuring, and uses an RGBIR sensor and a single lens.
However, in the RGBIR camera, RGB light is incident onto IR pixels as crosstalk, and IR light is incident onto RGB pixels as crosstalk. This may cause optical noise, and thus lower performance.